• Proceedings of the KIEE Conference
• /
• 1999.11a
• /
• pp.43-51
• /
• 1999

The power flow calculations(PFc) are the most important and powerful tools in power systems engineering. The conventional power flow problem is solved generally with numerical methods such as Newton-Raphson(NR). The conventional numerical method generally have some convergency problem, which is sensitive to initial value, and numerical stability problem concerned with jacobian matrix inversion. This paper presents a new PFc algorithm based on the improved genetic algorithm (IGA) which can overcome the disadvantages mentioned above. The parameters of GA, with dynamical hierarchy of the coding system, are improved to make GA a practical algorithm in the problem of real system. Some case studies with test bus system also present to show the performance of proposed algorithm. The results of proposed algorithm are compared with the results of PFc obtained using a conventional NR method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.04a
• /
• pp.194-197
• /
• 1997

The LB technique is one of the most powerful fabricating methods of organic ultra-thin film, which deposits a monolayer films in molecular level on the surface of the substrate. We have investigated the electrical characteristics of Myristic acid, Stearic acid and Arachidic acid LB films for horizontal direction to develop for the gas sensor. The optimum conditions for a film deposition were obtained by measurement of $\pi$-A isotherm. The status of the deposited film was confirmed by measurement of UV absorbance. We could distingished the difference of I-V characteristics for the fatty acid for the horizontal direction. The conductivity of fatty acid LB films for horizontal direction was 10$^{-7}$ ~ 10$^{-9}$ [S/cm] that mean like semiconductor.

• Proceedings of the KIEE Conference
• /
• 2000.11d
• /
• pp.718-720
• /
• 2000

Turbo Code is one of the most useful and powerful channel coding technique. It is adopted in radio transmission of IMT-2000, both CDMA2000 and W-CDMA system. The performance of this code depends on many parameters such as encoder memory size, free distance of codewords, interleaver size, number of decoding iteration, and so on. This paper describes a Multi-Stage Interleaver which is used in Turbo Codes for W-CDMA channel coding. We compare the performance of a Multi-Stage Interleaver with that of Mother Interleaver. The simulation results show that Multi-Stage Interleaver performs better than Mother Interleaver in bit error rate from $10^{-3}$ to $10^{-6}$.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.276-279
• /
• 2004

The location-based service is one of the most powerful services in the mobile area. The location-based service provides information service for moving user's location information and information service using wire / wireless communication. In this paper, we propose a model for personalized recommendation system which includes location information and personalized recommendation system for location-based service. For this service system, we consider mobile clients that have a limited resource and low bandwidth. Because it is difficult to input the words at mobile device, we must deliberate it when we design the interface of system. We design and implement the personalized recommendation system for location-based services(advertisement, discount news, and event information) that support user's needs and location information. As a result, it can be used to design the other location-based service systems related to user's location information in mobile environment. In this case, we need to establish formal definition of moving objects and their temporal pattern.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.1.2-6
• /
• 1994

A state or the arts in Japanese chemical process control is reviewed based on experience in applying advanced process control schemes to several industrial chemical processes. The applications validate model predictive control (MPC), the most popular advanced control scheme in the process control community, as, indeed, a powerful and practical control algorithm. However, at the same time, it is elucidated that MPC can solve only the control algorithm part of the problem and one needs chemical and systems engineering aspects to solve the entire problem. By illustrating several industrial process control problems, the need for chemical engineering aspects as well as the future direction for process control are addressed, especially in light or current attitudes toward product quality.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.113-118
• /
• 1993

This paper represents mechanical compliance & ZMP(Zero Moment Point) control algorithm for IWR(Inha Walking Robot) system. In case of walking in different environments, a biped walking robot must vary its gait(walking period or step length, etc.) according to the environments. However, most of biped walking robots do not have the capability to change their gaits or need more complex control algorithm, because ZMP cannot be defined in their control algorithm. Therefore new linear type with balancing joint is proposed which is used as an aid in balancing & ZMP control itself. In IWR system, ZMP can be defined by solving differential equations and it does not need to be predefined ZMP trajectory. Furthermore we can input the desired ZMP position. In parallel with the development, we also considered a mechanical compliance for reducing the inverse kinematics, dynamics and the control complexity. It will figure out some powerful adaptation with 3D irregular terrains.

• Journal of Korean Academy of Nursing
• /
• v.34 no.3
• /
• pp.576-585
• /
• 2004

Purpose: The purpose of this study was to identify the relationship between eating disorders, physical symptoms, depression and health locus of control. Method: The research design was a descriptive study done by using a constructive self-report questionnaire. A total of 464 elementary school girls were measured. The instrument was a constructive questionnaire that consisted 136 items. The subjects were divided into 4 groups according to the Body Mass Index (BMI). Data analysis was done by SPSS/WIN Programs using frequency, percentage, mean, SD, ANOVA, Pearson correlation coefficient, and stepwise multiple regression. Result: The score of eating disorders differed significantly by BMI : the score was highest in the group of obese students(F=4.208, P=.015). Stepwise multiple regression analysis revealed that the most powerful predictor of eating disorders was BMI. Conclusion: These results indicate that Korean elementary school girls need more education and counseling on diet. Also, we should take systematic efforts to reestablish the social standard of beauty to promote normal growth development.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.5 no.4
• /
• pp.195-205
• /
• 2010

The popularity of Smartphones makes new fields of applications based on location based service easily feasible with a new user interface called augmented reality (AR). It presents a particularly powerful user interface to context-aware computing environments. AR on Smartphones integrates virtual information into a person's physical environment by overlaying information on an image taken through Smartphone's camera and motion sensors. Mobile augmented reality systems provide this service without constraining the individual's whereabouts to a specially equipped area. This work presents an overview of handheld augmented reality focusing on applications with introducing the basic issues of them. For this purpose, an example system, Studierstube ES (embedded system), is cited, which introduces the most significant problems and various methods of solving them through the experience of converting existing PC-based AR system into handheld AR.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 1995.10a
• /
• pp.77-83
• /
• 1995

This study explores the patterns of housing-related attitudes and the kind of needs for shared community spaces among small-sized apartment housing dwellers. The major findings are as follows. The majority of the dwellers are in strong need of common spaces, especially for children's activities, Social gathering and physical exercises. Housing-related attitudes are found and grouped into 4categories the propensity to making up common society, the propensity to pursuing the quality of neighborhood, the propensity to orienting natural environment, and the propensity to participating in community. The intensity of the needs depends on family lifecycle, employment status of housewives, and the size of floor space. The propensity to making up common society and pursing the quality of neighborhood have stronger impact on needs of shared community space. This study reveals that the sense of community orientation is the most powerful predictor variable for shared community space needs .

• Research in Community and Public Health Nursing
• /
• v.18 no.1
• /
• pp.23-31
• /
• 2007

Purpose: This study was to investigate factors influencing the well-being of the aged in rural areas. Method: The subjects consisted of 250 elders living in rural areas of Kyungsangbuk-do. Data were collected by questionnaire surveys using convenience sampling. The instruments used in this study were the Well-being Scale by Chang (1999), the perceived health status developed by Speake, Cowart, and Pellet (1989), and the Social Support Scale developed by Song (1991). Data were analyzed using the SPSS program through descriptive statistics, t-test, ANOVA, Duncan's multiple-range test, Pearson Correlation Coefficient and stepwise multiple regression. Results: The most powerful predictor of well-being was social support, and then religion, health status, living expenses, and habitation accounted for 42.95% of variance in the well-being of the aged in rural areas. Conclusion: These results suggest that perceived health status and social support can be potential risk factors in the well-being of the aged. The findings of this study provide the basis of program development to improve the well-being of the aged in rural areas.